/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007  Josh Coalson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if HAVE_CONFIG_H
    #include <config.h>
#endif

#include <stdlib.h> /* for malloc() */
#include <string.h> /* for memcpy(), memset() */
#ifdef _MSC_VER
    #include <winsock.h> /* for ntohl() */
#elif defined FLAC__SYS_DARWIN
    #include <machine/endian.h> /* for ntohl() */
#elif defined __MINGW32__
    #include <winsock.h> /* for ntohl() */
#else
    #include <netinet/in.h> /* for ntohl() */
#endif
#if 0 /* UNUSED */
    #include "private/bitmath.h"
#endif
#include "private/bitwriter.h"
#include "private/crc.h"
#include "public/assert_flac.h"
#include "share/alloc.h"

/* Things should be fastest when this matches the machine word size */
/* WATCHOUT: if you change this you must also change the following #defines down to SWAP_BE_WORD_TO_HOST below to match */
/* WATCHOUT: there are a few places where the code will not work unless bwword is >= 32 bits wide */
typedef FLAC__uint32 bwword;
#define FLAC__BYTES_PER_WORD 4
#define FLAC__BITS_PER_WORD 32
#define FLAC__WORD_ALL_ONES ((FLAC__uint32)0xffffffff)
/* SWAP_BE_WORD_TO_HOST swaps bytes in a bwword (which is always big-endian) if necessary to match host byte order */
#if WORDS_BIGENDIAN
    #define SWAP_BE_WORD_TO_HOST(x) (x)
#else
    #ifdef _MSC_VER
        #define SWAP_BE_WORD_TO_HOST(x) local_swap32_(x)
    #else
        #define SWAP_BE_WORD_TO_HOST(x) ntohl(x)
    #endif
#endif

/*
 * The default capacity here doesn't matter too much.  The buffer always grows
 * to hold whatever is written to it.  Usually the encoder will stop adding at
 * a frame or metadata block, then write that out and clear the buffer for the
 * next one.
 */
static const unsigned FLAC__BITWRITER_DEFAULT_CAPACITY = 32768u / sizeof(bwword); /* size in words */
/* When growing, increment 4K at a time */
static const unsigned FLAC__BITWRITER_DEFAULT_INCREMENT = 4096u / sizeof(bwword); /* size in words */

#define FLAC__WORDS_TO_BITS(words) ((words) * FLAC__BITS_PER_WORD)
#define FLAC__TOTAL_BITS(bw) (FLAC__WORDS_TO_BITS((bw)->words) + (bw)->bits)

#ifdef min
    #undef min
#endif
#define min(x, y) ((x) < (y) ? (x) : (y))

/* adjust for compilers that can't understand using LLU suffix for uint64_t literals */
#ifdef _MSC_VER
    #define FLAC__U64L(x) x
#else
    #define FLAC__U64L(x) x##LLU
#endif

#ifndef FLaC__INLINE
    #define FLaC__INLINE
#endif

struct FLAC__BitWriter
{
    bwword* buffer;
    bwword accum; /* accumulator; bits are right-justified; when full, accum is appended to buffer */
    unsigned capacity; /* capacity of buffer in words */
    unsigned words; /* # of complete words in buffer */
    unsigned bits; /* # of used bits in accum */
};

#ifdef _MSC_VER
/* OPT: an MSVC built-in would be better */
static _inline FLAC__uint32 local_swap32_(FLAC__uint32 x)
{
    x = ((x << 8) & 0xFF00FF00) | ((x >> 8) & 0x00FF00FF);
    return (x >> 16) | (x << 16);
}
#endif

/* * WATCHOUT: The current implementation only grows the buffer. */
static FLAC__bool bitwriter_grow_(FLAC__BitWriter* bw, unsigned bits_to_add)
{
    unsigned new_capacity;
    bwword* new_buffer;

    FLAC__ASSERT(0 != bw);
    FLAC__ASSERT(0 != bw->buffer);

    /* calculate total words needed to store 'bits_to_add' additional bits */
    new_capacity = bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD);

    /* it's possible (due to pessimism in the growth estimation that
     * leads to this call) that we don't actually need to grow
     */
    if (bw->capacity >= new_capacity)
        return true;

    /* round up capacity increase to the nearest FLAC__BITWRITER_DEFAULT_INCREMENT */
    if ((new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT)
        new_capacity += FLAC__BITWRITER_DEFAULT_INCREMENT - ((new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT);
    /* make sure we got everything right */
    FLAC__ASSERT(0 == (new_capacity - bw->capacity) % FLAC__BITWRITER_DEFAULT_INCREMENT);
    FLAC__ASSERT(new_capacity > bw->capacity);
    FLAC__ASSERT(new_capacity >= bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD));

    new_buffer = (bwword*)safe_realloc_mul_2op_(bw->buffer, sizeof(bwword), /*times*/ new_capacity);
    if (new_buffer == 0)
        return false;
    bw->buffer = new_buffer;
    bw->capacity = new_capacity;
    return true;
}


/***********************************************************************
*
* Class constructor/destructor
*
***********************************************************************/

FLAC__BitWriter * FLAC__bitwriter_new()
{
    FLAC__BitWriter* bw = (FLAC__BitWriter*)calloc(1, sizeof(FLAC__BitWriter));
    /* note that calloc() sets all members to 0 for us */
    return bw;
}

void FLAC__bitwriter_delete(FLAC__BitWriter* bw)
{
    FLAC__ASSERT(0 != bw);

    FLAC__bitwriter_free(bw);
    free(bw);
}

/***********************************************************************
*
* Public class methods
*
***********************************************************************/

FLAC__bool FLAC__bitwriter_init(FLAC__BitWriter* bw)
{
    FLAC__ASSERT(0 != bw);

    bw->words = bw->bits = 0;
    bw->capacity = FLAC__BITWRITER_DEFAULT_CAPACITY;
    bw->buffer = (bwword*)malloc(sizeof(bwword) * bw->capacity);
    if (bw->buffer == 0)
        return false;

    return true;
}

void FLAC__bitwriter_free(FLAC__BitWriter* bw)
{
    FLAC__ASSERT(0 != bw);

    if (0 != bw->buffer)
        free(bw->buffer);
    bw->buffer = 0;
    bw->capacity = 0;
    bw->words = bw->bits = 0;
}

void FLAC__bitwriter_clear(FLAC__BitWriter* bw)
{
    bw->words = bw->bits = 0;
}

void FLAC__bitwriter_dump(const FLAC__BitWriter* bw, FILE* out)
{
    unsigned i, j;
    if (bw == 0)
    {
        fprintf(out, "bitwriter is nullptr\n");
    }
    else
    {
        fprintf(out, "bitwriter: capacity=%u words=%u bits=%u total_bits=%u\n", bw->capacity, bw->words, bw->bits, FLAC__TOTAL_BITS(bw));

        for (i = 0; i < bw->words; i++)
        {
            fprintf(out, "%08X: ", i);
            for (j = 0; j < FLAC__BITS_PER_WORD; j++)
                fprintf(out, "%01u", bw->buffer[i] & (1 << (FLAC__BITS_PER_WORD - j - 1)) ? 1 : 0);
            fprintf(out, "\n");
        }
        if (bw->bits > 0)
        {
            fprintf(out, "%08X: ", i);
            for (j = 0; j < bw->bits; j++)
                fprintf(out, "%01u", bw->accum & (1 << (bw->bits - j - 1)) ? 1 : 0);
            fprintf(out, "\n");
        }
    }
}

FLAC__bool FLAC__bitwriter_get_write_crc16(FLAC__BitWriter* bw, FLAC__uint16* crc)
{
    const FLAC__byte* buffer;
    size_t bytes;

    FLAC__ASSERT((bw->bits & 7) == 0); /* assert that we're byte-aligned */

    if (!FLAC__bitwriter_get_buffer(bw, &buffer, &bytes))
        return false;

    *crc = (FLAC__uint16)FLAC__crc16(buffer, bytes);
    FLAC__bitwriter_release_buffer(bw);
    return true;
}

FLAC__bool FLAC__bitwriter_get_write_crc8(FLAC__BitWriter* bw, FLAC__byte* crc)
{
    const FLAC__byte* buffer;
    size_t bytes;

    FLAC__ASSERT((bw->bits & 7) == 0); /* assert that we're byte-aligned */

    if (!FLAC__bitwriter_get_buffer(bw, &buffer, &bytes))
        return false;

    *crc = FLAC__crc8(buffer, bytes);
    FLAC__bitwriter_release_buffer(bw);
    return true;
}

FLAC__bool FLAC__bitwriter_is_byte_aligned(const FLAC__BitWriter* bw)
{
    return ((bw->bits & 7) == 0);
}

unsigned FLAC__bitwriter_get_input_bits_unconsumed(const FLAC__BitWriter* bw)
{
    return FLAC__TOTAL_BITS(bw);
}

FLAC__bool FLAC__bitwriter_get_buffer(FLAC__BitWriter* bw, const FLAC__byte** buffer, size_t* bytes)
{
    FLAC__ASSERT((bw->bits & 7) == 0);
    /* double protection */
    if (bw->bits & 7)
        return false;
    /* if we have bits in the accumulator we have to flush those to the buffer first */
    if (bw->bits)
    {
        FLAC__ASSERT(bw->words <= bw->capacity);
        if (bw->words == bw->capacity && !bitwriter_grow_(bw, FLAC__BITS_PER_WORD))
            return false;
        /* append bits as complete word to buffer, but don't change bw->accum or bw->bits */
        bw->buffer[bw->words] = SWAP_BE_WORD_TO_HOST(bw->accum << (FLAC__BITS_PER_WORD - bw->bits));
    }
    /* now we can just return what we have */
    *buffer = (FLAC__byte*)bw->buffer;
    *bytes = (FLAC__BYTES_PER_WORD * bw->words) + (bw->bits >> 3);
    return true;
}

void FLAC__bitwriter_release_buffer(FLAC__BitWriter* bw)
{
    /* nothing to do.  in the future, strict checking of a 'writer-is-in-
     * get-mode' flag could be added everywhere and then cleared here
     */
    bw;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_zeroes(FLAC__BitWriter* bw, unsigned bits)
{
    unsigned n;

    FLAC__ASSERT(0 != bw);
    FLAC__ASSERT(0 != bw->buffer);

    if (bits == 0)
        return true;
    /* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
    if (bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
        return false;
    /* first part gets to word alignment */
    if (bw->bits)
    {
        n = min(FLAC__BITS_PER_WORD - bw->bits, bits);
        bw->accum <<= n;
        bits -= n;
        bw->bits += n;
        if (bw->bits == FLAC__BITS_PER_WORD)
        {
            bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
            bw->bits = 0;
        }
        else
            return true;
    }
    /* do whole words */
    while (bits >= FLAC__BITS_PER_WORD)
    {
        bw->buffer[bw->words++] = 0;
        bits -= FLAC__BITS_PER_WORD;
    }
    /* do any leftovers */
    if (bits > 0)
    {
        bw->accum = 0;
        bw->bits = bits;
    }
    return true;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter* bw, FLAC__uint32 val, unsigned bits)
{
    register unsigned left;

    /* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
    FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);

    FLAC__ASSERT(0 != bw);
    FLAC__ASSERT(0 != bw->buffer);

    FLAC__ASSERT(bits <= 32);
    if (bits == 0)
        return true;

    /* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
    if (bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
        return false;

    left = FLAC__BITS_PER_WORD - bw->bits;
    if (bits < left)
    {
        bw->accum <<= bits;
        bw->accum |= val;
        bw->bits += bits;
    }
    else if (bw->bits)   /* WATCHOUT: if bw->bits == 0, left==FLAC__BITS_PER_WORD and bw->accum<<=left is a NOP instead of setting to 0 */
    {
        bw->accum <<= left;
        bw->accum |= val >> (bw->bits = bits - left);
        bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
        bw->accum = val;
    }
    else
    {
        bw->accum = val;
        bw->bits = 0;
        bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(val);
    }

    return true;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter* bw, FLAC__int32 val, unsigned bits)
{
    /* zero-out unused bits */
    if (bits < 32)
        val &= (~(0xffffffff << bits));

    return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter* bw, FLAC__uint64 val, unsigned bits)
{
    /* this could be a little faster but it's not used for much */
    if (bits > 32)
    {
        return
            FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(val >> 32), bits - 32) &&
            FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, 32);
    }
    else
        return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter* bw, FLAC__uint32 val)
{
    /* this doesn't need to be that fast as currently it is only used for vorbis comments */

    if (!FLAC__bitwriter_write_raw_uint32(bw, val & 0xff, 8))
        return false;
    if (!FLAC__bitwriter_write_raw_uint32(bw, (val >> 8) & 0xff, 8))
        return false;
    if (!FLAC__bitwriter_write_raw_uint32(bw, (val >> 16) & 0xff, 8))
        return false;
    if (!FLAC__bitwriter_write_raw_uint32(bw, val >> 24, 8))
        return false;

    return true;
}

FLaC__INLINE FLAC__bool FLAC__bitwriter_write_byte_block(FLAC__BitWriter* bw, const FLAC__byte vals[], unsigned nvals)
{
    unsigned i;

    /* this could be faster but currently we don't need it to be since it's only used for writing metadata */
    for (i = 0; i < nvals; i++)
    {
        if (!FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(vals[i]), 8))
            return false;
    }

    return true;
}

FLAC__bool FLAC__bitwriter_write_unary_unsigned(FLAC__BitWriter* bw, unsigned val)
{
    if (val < 32)
        return FLAC__bitwriter_write_raw_uint32(bw, 1, ++val);
    else
        return
            FLAC__bitwriter_write_zeroes(bw, val) &&
            FLAC__bitwriter_write_raw_uint32(bw, 1, 1);
}

unsigned FLAC__bitwriter_rice_bits(FLAC__int32 val, unsigned parameter)
{
    FLAC__uint32 uval;

    FLAC__ASSERT(parameter < sizeof(unsigned) * 8);

    /* fold signed to unsigned; actual formula is: negative(v)? -2v-1 : 2v */
    uval = (val << 1) ^ (val >> 31);

    return 1 + parameter + (uval >> parameter);
}

#if 0 /* UNUSED */
unsigned FLAC__bitwriter_golomb_bits_signed(int val, unsigned parameter)
{
    unsigned bits, msbs, uval;
    unsigned k;

    FLAC__ASSERT(parameter > 0);

    /* fold signed to unsigned */
    if (val < 0)
        uval = (unsigned)(((-(++val)) << 1) + 1);
    else
        uval = (unsigned)(val << 1);

    k = FLAC__bitmath_ilog2(parameter);
    if (parameter == 1u << k)
    {
        FLAC__ASSERT(k <= 30);

        msbs = uval >> k;
        bits = 1 + k + msbs;
    }
    else
    {
        unsigned q, r, d;

        d = (1 << (k + 1)) - parameter;
        q = uval / parameter;
        r = uval - (q * parameter);

        bits = 1 + q + k;
        if (r >= d)
            bits++;
    }
    return bits;
}

unsigned FLAC__bitwriter_golomb_bits_unsigned(unsigned uval, unsigned parameter)
{
    unsigned bits, msbs;
    unsigned k;

    FLAC__ASSERT(parameter > 0);

    k = FLAC__bitmath_ilog2(parameter);
    if (parameter == 1u << k)
    {
        FLAC__ASSERT(k <= 30);

        msbs = uval >> k;
        bits = 1 + k + msbs;
    }
    else
    {
        unsigned q, r, d;

        d = (1 << (k + 1)) - parameter;
        q = uval / parameter;
        r = uval - (q * parameter);

        bits = 1 + q + k;
        if (r >= d)
            bits++;
    }
    return bits;
}
#endif /* UNUSED */

FLAC__bool FLAC__bitwriter_write_rice_signed(FLAC__BitWriter* bw, FLAC__int32 val, unsigned parameter)
{
    unsigned total_bits, interesting_bits, msbs;
    FLAC__uint32 uval, pattern;

    FLAC__ASSERT(0 != bw);
    FLAC__ASSERT(0 != bw->buffer);
    FLAC__ASSERT(parameter < 8 * sizeof(uval));

    /* fold signed to unsigned; actual formula is: negative(v)? -2v-1 : 2v */
    uval = (val << 1) ^ (val >> 31);

    msbs = uval >> parameter;
    interesting_bits = 1 + parameter;
    total_bits = interesting_bits + msbs;
    pattern = 1 << parameter; /* the unary end bit */
    pattern |= (uval & ((1 << parameter) - 1)); /* the binary LSBs */

    if (total_bits <= 32)
        return FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits);
    else
        return
            FLAC__bitwriter_write_zeroes(bw, msbs) && /* write the unary MSBs */
            FLAC__bitwriter_write_raw_uint32(bw, pattern, interesting_bits); /* write the unary end bit and binary LSBs */
}

FLAC__bool FLAC__bitwriter_write_rice_signed_block(FLAC__BitWriter* bw, const FLAC__int32* vals, unsigned nvals, unsigned parameter)
{
    const FLAC__uint32 mask1 = FLAC__WORD_ALL_ONES << parameter; /* we val|=mask1 to set the stop bit above it... */
    const FLAC__uint32 mask2 = FLAC__WORD_ALL_ONES >> (31 - parameter); /* ...then mask off the bits above the stop bit with val&=mask2*/
    FLAC__uint32 uval;
    unsigned left;
    const unsigned lsbits = 1 + parameter;
    unsigned msbits;

    FLAC__ASSERT(0 != bw);
    FLAC__ASSERT(0 != bw->buffer);
    FLAC__ASSERT(parameter < 8 * sizeof(bwword) - 1);
    /* WATCHOUT: code does not work with <32bit words; we can make things much faster with this assertion */
    FLAC__ASSERT(FLAC__BITS_PER_WORD >= 32);

    while (nvals)
    {
        /* fold signed to unsigned; actual formula is: negative(v)? -2v-1 : 2v */
        uval = (*vals << 1) ^ (*vals >> 31);

        msbits = uval >> parameter;

        #if 0 /* OPT: can remove this special case if it doesn't make up for the extra compare (doesn't make a statistically significant difference with msvc or gcc/x86) */
        if (bw->bits && bw->bits + msbits + lsbits <= FLAC__BITS_PER_WORD)   /* i.e. if the whole thing fits in the current bwword */
        {   /* ^^^ if bw->bits is 0 then we may have filled the buffer and have no free bwword to work in */
            bw->bits = bw->bits + msbits + lsbits;
            uval |= mask1; /* set stop bit */
            uval &= mask2; /* mask off unused top bits */
            /* NOT: bw->accum <<= msbits + lsbits because msbits+lsbits could be 32, then the shift would be a NOP */
            bw->accum <<= msbits;
            bw->accum <<= lsbits;
            bw->accum |= uval;
            if (bw->bits == FLAC__BITS_PER_WORD)
            {
                bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
                bw->bits = 0;
                /* burying the capacity check down here means we have to grow the buffer a little if there are more vals to do */
                if (bw->capacity <= bw->words && nvals > 1 && !bitwriter_grow_(bw, 1))
                {
                    FLAC__ASSERT(bw->capacity == bw->words);
                    return false;
                }
            }
        }
        else
        {
        #elif 1 /*@@@@@@ OPT: try this version with MSVC6 to see if better, not much difference for gcc-4 */
        if (bw->bits && bw->bits + msbits + lsbits < FLAC__BITS_PER_WORD)   /* i.e. if the whole thing fits in the current bwword */
        {   /* ^^^ if bw->bits is 0 then we may have filled the buffer and have no free bwword to work in */
            bw->bits = bw->bits + msbits + lsbits;
            uval |= mask1; /* set stop bit */
            uval &= mask2; /* mask off unused top bits */
            bw->accum <<= msbits + lsbits;
            bw->accum |= uval;
        }
        else
        {
            #endif
            /* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+msbits+lsbits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
            /* OPT: pessimism may cause flurry of false calls to grow_ which eat up all savings before it */
            if (bw->capacity <= bw->words + bw->bits + msbits + 1 /*lsbits always fit in 1 bwword*/ && !bitwriter_grow_(bw, msbits + lsbits))
                return false;

            if (msbits)
            {
                /* first part gets to word alignment */
                if (bw->bits)
                {
                    left = FLAC__BITS_PER_WORD - bw->bits;
                    if (msbits < left)
                    {
                        bw->accum <<= msbits;
                        bw->bits += msbits;
                        goto break1;
                    }
                    else
                    {
                        bw->accum <<= left;
                        msbits -= left;
                        bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
                        bw->bits = 0;
                    }
                }
                /* do whole words */
                while (msbits >= FLAC__BITS_PER_WORD)
                {
                    bw->buffer[bw->words++] = 0;
                    msbits -= FLAC__BITS_PER_WORD;
                }
                /* do any leftovers */
                if (msbits > 0)
                {
                    bw->accum = 0;
                    bw->bits = msbits;
                }
            }
break1:
            uval |= mask1; /* set stop bit */
            uval &= mask2; /* mask off unused top bits */

            left = FLAC__BITS_PER_WORD - bw->bits;
            if (lsbits < left)
            {
                bw->accum <<= lsbits;
                bw->accum |= uval;
                bw->bits += lsbits;
            }
            else
            {
                /* if bw->bits == 0, left==FLAC__BITS_PER_WORD which will always
                 * be > lsbits (because of previous assertions) so it would have
                 * triggered the (lsbits<left) case above.
                 */
                FLAC__ASSERT(bw->bits);
                FLAC__ASSERT(left < FLAC__BITS_PER_WORD);
                bw->accum <<= left;
                bw->accum |= uval >> (bw->bits = lsbits - left);
                bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
                bw->accum = uval;
            }
            #if 1
        }
            #endif
            vals++;
            nvals--;
        }
        return true;
    }

    #if 0 /* UNUSED */
    FLAC__bool FLAC__bitwriter_write_golomb_signed(FLAC__BitWriter* bw, int val, unsigned parameter)
    {
        unsigned total_bits, msbs, uval;
        unsigned k;

        FLAC__ASSERT(0 != bw);
        FLAC__ASSERT(0 != bw->buffer);
        FLAC__ASSERT(parameter > 0);

        /* fold signed to unsigned */
        if (val < 0)
            uval = (unsigned)(((-(++val)) << 1) + 1);
        else
            uval = (unsigned)(val << 1);

        k = FLAC__bitmath_ilog2(parameter);
        if (parameter == 1u << k)
        {
            unsigned pattern;

            FLAC__ASSERT(k <= 30);

            msbs = uval >> k;
            total_bits = 1 + k + msbs;
            pattern = 1 << k; /* the unary end bit */
            pattern |= (uval & ((1u << k) - 1)); /* the binary LSBs */

            if (total_bits <= 32)
            {
                if (!FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits))
                    return false;
            }
            else
            {
                /* write the unary MSBs */
                if (!FLAC__bitwriter_write_zeroes(bw, msbs))
                    return false;
                /* write the unary end bit and binary LSBs */
                if (!FLAC__bitwriter_write_raw_uint32(bw, pattern, k + 1))
                    return false;
            }
        }
        else
        {
            unsigned q, r, d;

            d = (1 << (k + 1)) - parameter;
            q = uval / parameter;
            r = uval - (q * parameter);
            /* write the unary MSBs */
            if (!FLAC__bitwriter_write_zeroes(bw, q))
                return false;
            /* write the unary end bit */
            if (!FLAC__bitwriter_write_raw_uint32(bw, 1, 1))
                return false;
            /* write the binary LSBs */
            if (r >= d)
            {
                if (!FLAC__bitwriter_write_raw_uint32(bw, r + d, k + 1))
                    return false;
            }
            else
            {
                if (!FLAC__bitwriter_write_raw_uint32(bw, r, k))
                    return false;
            }
        }
        return true;
    }

    FLAC__bool FLAC__bitwriter_write_golomb_unsigned(FLAC__BitWriter* bw, unsigned uval, unsigned parameter)
    {
        unsigned total_bits, msbs;
        unsigned k;

        FLAC__ASSERT(0 != bw);
        FLAC__ASSERT(0 != bw->buffer);
        FLAC__ASSERT(parameter > 0);

        k = FLAC__bitmath_ilog2(parameter);
        if (parameter == 1u << k)
        {
            unsigned pattern;

            FLAC__ASSERT(k <= 30);

            msbs = uval >> k;
            total_bits = 1 + k + msbs;
            pattern = 1 << k; /* the unary end bit */
            pattern |= (uval & ((1u << k) - 1)); /* the binary LSBs */

            if (total_bits <= 32)
            {
                if (!FLAC__bitwriter_write_raw_uint32(bw, pattern, total_bits))
                    return false;
            }
            else
            {
                /* write the unary MSBs */
                if (!FLAC__bitwriter_write_zeroes(bw, msbs))
                    return false;
                /* write the unary end bit and binary LSBs */
                if (!FLAC__bitwriter_write_raw_uint32(bw, pattern, k + 1))
                    return false;
            }
        }
        else
        {
            unsigned q, r, d;

            d = (1 << (k + 1)) - parameter;
            q = uval / parameter;
            r = uval - (q * parameter);
            /* write the unary MSBs */
            if (!FLAC__bitwriter_write_zeroes(bw, q))
                return false;
            /* write the unary end bit */
            if (!FLAC__bitwriter_write_raw_uint32(bw, 1, 1))
                return false;
            /* write the binary LSBs */
            if (r >= d)
            {
                if (!FLAC__bitwriter_write_raw_uint32(bw, r + d, k + 1))
                    return false;
            }
            else
            {
                if (!FLAC__bitwriter_write_raw_uint32(bw, r, k))
                    return false;
            }
        }
        return true;
    }
    #endif /* UNUSED */

    FLAC__bool FLAC__bitwriter_write_utf8_uint32(FLAC__BitWriter* bw, FLAC__uint32 val)
    {
        FLAC__bool ok = 1;

        FLAC__ASSERT(0 != bw);
        FLAC__ASSERT(0 != bw->buffer);

        FLAC__ASSERT(!(val & 0x80000000)); /* this version only handles 31 bits */

        if (val < 0x80)
        {
            return FLAC__bitwriter_write_raw_uint32(bw, val, 8);
        }
        else if (val < 0x800)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xC0 | (val >> 6), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val & 0x3F), 8);
        }
        else if (val < 0x10000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xE0 | (val >> 12), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val & 0x3F), 8);
        }
        else if (val < 0x200000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF0 | (val >> 18), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val & 0x3F), 8);
        }
        else if (val < 0x4000000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF8 | (val >> 24), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 18) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val & 0x3F), 8);
        }
        else
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFC | (val >> 30), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 24) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 18) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val & 0x3F), 8);
        }

        return ok;
    }

    FLAC__bool FLAC__bitwriter_write_utf8_uint64(FLAC__BitWriter* bw, FLAC__uint64 val)
    {
        FLAC__bool ok = 1;

        FLAC__ASSERT(0 != bw);
        FLAC__ASSERT(0 != bw->buffer);

        FLAC__ASSERT(!(val & FLAC__U64L(0xFFFFFFF000000000))); /* this version only handles 36 bits */

        if (val < 0x80)
        {
            return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, 8);
        }
        else if (val < 0x800)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xC0 | (FLAC__uint32)(val >> 6), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val & 0x3F), 8);
        }
        else if (val < 0x10000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xE0 | (FLAC__uint32)(val >> 12), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val & 0x3F), 8);
        }
        else if (val < 0x200000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF0 | (FLAC__uint32)(val >> 18), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val & 0x3F), 8);
        }
        else if (val < 0x4000000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF8 | (FLAC__uint32)(val >> 24), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 18) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val & 0x3F), 8);
        }
        else if (val < 0x80000000)
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFC | (FLAC__uint32)(val >> 30), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 24) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 18) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val & 0x3F), 8);
        }
        else
        {
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFE, 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 30) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 24) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 18) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 12) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val >> 6) & 0x3F), 8);
            ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val & 0x3F), 8);
        }

        return ok;
    }

    FLAC__bool FLAC__bitwriter_zero_pad_to_byte_boundary(FLAC__BitWriter* bw)
    {
        /* 0-pad to byte boundary */
        if (bw->bits & 7u)
            return FLAC__bitwriter_write_zeroes(bw, 8 - (bw->bits & 7u));
        else
            return true;
    }